ben tracy, cbs news, los angeles. >> pelley: today the u.s. military made a point of ignoring a new directive from china. it flew two american b-52 bombers over dispute islands that are claimed by both china and japan. over the weekend, china said that it had to approve any flights there. but the u.s. considers this international airspace. the b-52s had no problem. tonight, president obama's national security adviser is flying home from afghanistan and empty-handed. susan rice's mission was to persuade afghan president hamid karzai to sign a new security agreement that will keep some u.s. troops in afghanistan after the nato combat mission ends after next year. major gar marrett's at the white house. >> reporter: the white house says president karzai holds in his hans the future security of his country and the promise of $8 billion in annual u.s. aid. that hand currently will not sient security agreement the u.s. thought was sealed and delivered. national security adviser susan rice's face-to-face meeting with the afghan president produced not